window.makeEstimates = function(){ var estimateScale = d3.scaleLinear() .domain([.5 - .15, .5 + .15]).range([0, c.width]) .interpolate(d3.interpolateRound) var jitterHeight = 90 var rs = 4 // rect size var estimates = students[0].coinVals.map(d => ({val: .5, pctHead: .25, x: c.width/2, y: c.height - jitterHeight/2})) var simulation = d3.forceSimulation(estimates) .force('collide', d3.forceCollide(rs).strength(.1)) .stop() function updateEstimates(){ var selectedStudents = students.all.slice(0, sliders.population) selectedStudents[0].coinVals.map((_, i) => { estimates[i].pctHead = d3.mean(selectedStudents, d => (d.coinVals[i] < sliders.headsProb) || d.plagerized) estimates[i].val = (1 - estimates[i].pctHead)/(1 - sliders.headsProb) }) updateSimulation(60) } updateEstimates() function updateSimulation(ticks=80, yStrength=.005){ var variance = d3.variance(estimates, d => d.val) var xStength = variance < .0005 ? .3 : .1 estimates.forEach(d => d.targetX = estimateScale(d.val)) simulation .force('x', d3.forceX(d => d.targetX).strength(xStength)) .force('y', d3.forceY(c.height - jitterHeight/2).strength(yStrength)) .alpha(1) // .alphaDecay(1 - Math.pow(0.001, 1/ticks)) for (var i = 0; i < ticks; ++i) simulation.tick() estimates.forEach(d => { d.x = Math.round(d.x) d.y = Math.round(d.y) }) } updateSimulation(80, 1) updateSimulation(80, .005) // Set up DOM var histogramSel = c.svg.append('g').translate([0, -25]) var axisSel = histogramSel.append('g.axis.state.init-hidden') var histogramAxis = axisSel.append('g') var numTicks = 6 var xAxis = d3.axisTop(estimateScale).ticks(numTicks).tickFormat(d3.format('.0%')).tickSize(100) histogramAxis.call(xAxis).translate([.5, c.height + 5]) middleTick = histogramAxis.selectAll('g').filter((d, i) => i === 3) middleTick.select('text').classed('bold', 1) middleTick.select('line').st({stroke: '#000'}) histogramAxis.append('text.bold') .text('actual non-plagiarism rate') .translate([c.width/2, 11]) .st({fontSize: '10px'}) var containerSel = histogramSel.append('g#histogram').translate([0.5, .5]) // Selection overlay to highlight individual estimates. var selectSize = rs*2 + 2 var selectColor = '#007276' var rectFill = '#007276' var activeSel = histogramSel.append('g.active.init-hidden.axis') .st({pointerEvents: 'none'}) activeSel.append('rect') .at({width: selectSize, height: selectSize, stroke: selectColor, fill: 'none', strokeWidth: 3}) .translate([-selectSize/2, -selectSize/2]) var activeTextHighlight = activeSel.append('rect') .at({x: -32, width: 32*2, height: 18, y: -25, fill: 'rgba(255,255,255,.6)', rx: 10, ry: 10, xfill: 'red'}) var activeTextSel = activeSel.append('text.est-text.bold') .text('34%') .at({textAnchor: 'middle', textAnchor: 'middle', y: '-1em'}) .st({fill: selectColor}) var activePathSel = activeSel.append('path') .st({stroke: selectColor, strokeWidth: 3}) // Update highlight DOM with current highlight var curDrawData = {pctHead: .25, val: .5, x: c.width/2, y: c.height - jitterHeight/2} function setActive(active, dur=0){ if (active !== estimates.active){ estimates.forEach(d => { d.active = d == active d.fy = d.active ? d.y : null }) estimates.active = active } students.updateHeadsPos() sel.flipCircle .transition().duration(0).delay(d => d.i*5*(dur > 0 ? 1 : 0)) .at({transform: d => slides && slides.curSlide && slides.curSlide.showFlipCircle && d.coinVals[active.index] < sliders.headsProb ? 'scale(1)' : 'scale(.1)'}) flipCoinTimer.stop() if (dur){ var objI = d3.interpolateObject(curDrawData, active) flipCoinTimer = d3.timer(ms => { var t = d3.easeCubicInOut(d3.clamp(0, ms/dur, 1)) drawData(objI(t)) if (t == 1) flipCoinTimer.stop() }) } else{ drawData(active) } function drawData({pctHead, val, x, y}){ activeSel.translate([x + rs/2, y + rs/2]) activeTextSel.text('est. ' + d3.format('.1%')(val)) activePathSel.at({d: `M ${selectSize/2*Math.sign(c.width/2 - x)} -1 H ${c.width/2 - x}`}) var error = Math.abs(val - .5) var fmt = d3.format(".1%") var pop = sliders.population d3.select('.rand-text') // .html(`${fmt(1 - pctHead)} of students said they had never plagerized. Since about half the students flipped heads and automatically reported plagerizism, we double that to estimate ${fmt(val)} of students haven't plagerized—${error > .1 ? '' : error > .07 ? 'a little ' : 'not '}far from the actual rate of ${fmt(.5)}`) // .html(`${Math.round((1 - pctHead)*pop)} of ${pop} students said they had never plagiarized. Since about half the students flipped heads and automatically reported plagiarism, we double that rate to estimate ${fmt(val)} of students haven't plagiarized—${error > .4 ? '' : error > .07 ? 'a little ' : 'not '}far from the actual rate of ${fmt(.5)}`) .html(`Here, ${fmt(1 - pctHead)} students said they had never plagiarized. Doubling that, we estimate ${fmt(val)} of students haven't plagiarized—${error > .1 ? 'quite ' : error > .07 ? 'a little ' : 'not '}far from the actual rate of ${fmt(.5)}`) curDrawData = {pctHead, val, x, y} } } window.flipCoinTimer = d3.timer(d => d) var estimateSel = containerSel.appendMany('rect.estimate', estimates) .at({width: rs, height: rs, stroke: '#fff', fill: rectFill, strokeWidth: .5}) .st({fill: rectFill}) .translate([rs/2, rs/2]) .on('mouseover', (d, i) => { if (window.slides.curSlide.showHistogram) { setActive(d) } }) function setSelectorOpacity(textOpacity, strokeOpacity) { activeTextSel.st({opacity: textOpacity}) activeSel.st({opacity: strokeOpacity}) activePathSel.st({opacity: strokeOpacity}) } function render(transition=false){ estimateSel.translate(d => [d.x, d.y]) setActive(estimates.active) if (transition){ if (window.flipAllCoinsTimer) window.flipAllCoinsTimer.stop() window.flipAllCoinsTimer = d3.timer(ms => { var t = d3.easeExpIn(d3.clamp(0, ms/5000, 1), 20) if (flipAllCoinsTimer.forceEnd) t = 1 if (t > .028) { setSelectorOpacity(textOpacity=0, strokeOpacity=0.7) } var index = Math.floor((estimates.length - 2)*t) + 1 estimateSel.classed('active', (d, i) => i <= index) setActive(estimates[index]) // flipCoinsSel.text('Flip coins ' + d3.format('03')(index < 100 ? index : index + 1) + ' times') flipCoinsSel.text('Flip coins 200 times') if (t == 1) { flipAllCoinsTimer.stop() setSelectorOpacity(textOpacity=1, strokeOpacity=1) } }) } else { setSelectorOpacity(textOpacity=1, strokeOpacity=1) flipCoinsSel } } window.flipAllCoinsTimer = d3.timer(d => d) var flipCoinsSel = d3.select('.flip-coins').on('click', () => { students.all.forEach(student => { student.coinVals = student.coinVals.map(j => Math.random()) }) updateEstimates() render(true) }) d3.select('.flip-coins-once').on('click', flipCoin) function flipCoin(){ active = estimates[0] students.all.forEach(student => { student.coinVals = student.coinVals.map(j => Math.random()) }) active.fy = active.y = c.height - jitterHeight/2 updateEstimates() estimateSel.translate(d => [d.x, d.y]) estimates.active = null setActive(active, 1000) } Object.assign(estimates, {updateEstimates, setActive, render, flipCoin, axisSel, containerSel, estimateSel, activeSel}) return estimates } if (window.init) window.init()